Craft beer is an expanding industry and growlers are convenient containers for the transport of beer from source to home or another desired location. Carbonated beverages, like beer, are fragile and susceptible to deterioration in quality due to a variety of factors including exposure to air or contaminants, such as mold, and the loss of carbonation. The loss of carbonation produces flatness. Contact with air can cause staleness due to oxidation and also affect mouth-feel and the taste of the beverage. Numerous solutions have been proposed to limit air contact. Of relevance here, are the solutions proposed in U.S. Published Application No. 2011/0278297 and U.S. Published Application No. 2014/0246396 since they propose solutions that address beverage contact with air in the head space of a container. The '297 application employs an inflatable bladder to keep the beverage separated from air but the beverage cannot be accessed simultaneously with the bladder excluding air from the vessel, instead the bladder must be deflated and removed to access the beverage and then reinserted and reinflated to reseal the beverage, exposing the beverage to air and promoting oxidation each time these actions are performed. The '396 application employs a rather complex system to minimize air contact with the carbonated beverage. A threaded cap is used to introduce a bladder system to a container. The cap includes an attached dual bladder system, which is used to displace the headspace in a beverage container by either pumping air into the bladder or pressurizing the bladder with carbon dioxide to displace the headspace gas out through a vent in the cap. The inner bladder is designed to hold the pressurized gas without stretching while the outer bladder surrounding the inner bladder is elastic in order to minimize the space the bladders occupy when empty. The use of the system is limited since its use requires a sealed container to have been partially emptied. In addition, the system is complex and presents many challenges and opportunities for failure.
There exists a need for a simpler design that addresses the headspace air contact with the beverage and also aids in dispensing the carbonated beverage without the need of a pressurized system. The systems described above required pressures greater than atmospheric pressure generated by adding compressed air, carbon dioxide, or nitrogen to dispense the beverage.